Authorities have intercepted more than $103 million worth of counterfeit American cash made in Peru over the past decade. But most of the total was confiscated since 2010, indicating a sharp surge in counterfeiting in recent years.

Peruvian counterfeiters show considerable skill, using children to insert security strips in the fake notes, which are hand-finished.

Despite the quality of the bills, Peruvian counterfeiters still rely on common bond paper, rather than the special cotton/linen material used by the U.S. Treasury, which makes the fakes easier to spot.

The ascendancy of Peru in both the drug trade and counterfeiting comes after years of U.S. efforts to combat the practices in Columbia. The U.S. Secret Service has been working in Peru since last year to try and counter the stream of fake bills.